Harmonic suppression and reactive control of NQ station in Genan HVDC system

This article has analyzed the origin and the harm of harmonics in the HVDC system. The harmonics analysis has been done to the DC and AC side of NQ substation in Ge-Nan HVDC system. And found the order 13 harmonic filters capacities are insufficient, so DA32 capacitor group will be transformed into HP11.8 filter. The reactive power control method of NQ station is also introduced in this paper, especially Umax, Q-control and Qmax control algorithms. The tests validated the AC filter switching sequence. The reason of F1 group filters must be devoted firstly before the HVDC system starts is analyzed.